There may be cheering on this forum as a result of the Speakers actions yesterday.
However this overlooks the fact that not onlyis the speaker highly partisan(why else a "bollocks to brexit" in his car) but on procedural matters he is "guided" by the clerk of the house.viz.
Chief procedural adviser

In the absence of a Speaker vested with formal powers of order the Clerk of the Parliaments is expected actively to provide authoritative advice on procedural matters on a daily basis to the Lord Speaker, the Leader of the House and other Members of the frontbenches, the Chairman of Committees and individual Members.

The Clerk of Parliaments sits for a significant proportion of each day in the Chamber of the House, and keeps a supervisory watch over its proceedings. He calls on the business of the House and participates in certain ceremonial occasions.

The fact the speaker is rather coy on the matter of either accepting or disregarding the advice of the clerk is significant.
He has done no favours to himself, Parliament or democracy.

Ex-ministers, constitutional experts and respected former Speaker Betty Boothroyd united in a chorus of anger over the Commons "stitch-up" that led to a Government defeat. COMMONS Speaker John Bercow was last night told to quit after "disgracefully" flouting parliamentary rules to help Remainers seize more control over Brexit.

The above could be regarded as "sour grapes" but when the highly respected former speaker Betty Boothroyd joins the chorus,I feel the allegations have substance.

or as another sees it:
A few weeks ago I made reference in an article to the fact that the Speaker’s car sported a sticker declaring “Bollocks to Brexit”. Within minutes, his defenders had got in touch to inform me that the sticker was affixed to his wife’s car, not his. This seemed to matter. It does not. No one surely now claims that Bercow is anything other than an anti-Brexit partisan cheering his side’s efforts to thwart our departure from the European Union from the safety of the Commons chair.

His bizarre and dangerous ruling in the Commons today, in favour of selecting an amendment by former Attorney General (and arch Remainer) Dominic Grieve, proposing that the Prime Minister be given a maximum of three days (instead of the current 21) to return to the Commons with a plan B if her withdrawal agreement is rejected by MPs next week, is proof positive of his political position. It is now accepted that his own clerk advised against the constitutionality of allowing the amendment to proceed, and that Bercow overruled him and others of the same opinion.

In some senses the fact of selecting the amendment, and the effect it would have if passed, change very little. On the first point, it will come as no surprise that Bercow opposes Britain’s exit from the EU and is comfortable using his authority in order to prevent it happening. This has been an accepted fact of life at Westminster since before the 2016 referendum.

Virtually every Labour MP in the Commons, formerly proud advocates of women’s and workers’ rights to workplaces free from bullying, chose to suspend that particular principle last year when serious accusations against the Speaker, from more than one reliable source, emerged. Normally – and especially if such allegations had involved a Conservative minister – Labour would have demanded immediate action. But in Bercow’s case – as lucidly explained by Dame Margaret Beckett MP – the cause of opposing Brexit trumps any less important issue such as the rights of Commons members of staff.