50% is not reasonable. 0% is reasonable.

If the local school with good attainment figures had a clause that your parents had to be stamp collectors, would you think that is a good use of your tax payer's investment? Even if it were only 50%?

Religion is an important subject in the abstract, just like history, geography etc. It helps understand where we are and how we ended up noting differences between people rather than similarities. I really do think RE is important, if only so older children can see the damage it does and choose to dismiss it on a personal level, or embrace it after objective reasoning if they choose.

No faith school does this. None whatsoever.