It turns out that one of the Lynnsights afforded us an insight as to why this might be. Lynn had gone into great detail about how her mother told her that not only was she too young to wear cosmetics, Ursula's own limited and rarely-used collection was not to be rifled though; her response was to take all of the used-up samples her mother's Avon Lady friend gave her and create a sort of cross between lip-stick and lip-gloss. Upon discovering this little experiment, Mrs Ridgway lectured her about sneaking around and still being a bit young; her buying Lynn a tube of lip gloss to avoid a repeat performance seemed to have the curious side effect of getting Lynn to not wear it because the thrill of the hunt had been spoiled.
This leaves us with two things to have to remind ourselves of. The first thing, of course, is that Lynn is something of an immature twit who loves to see what she can get away with; that means that she can't simply ask for something because she'd be denied the pleasure of being sneaky. The next is that her pet assumption would be proven wrong; after all, she went in assuming that "too young" meant "never" when, as we saw, it meant "if you prove that you want it enough." Rather than admit that she deliberately misread the situation out of a pride so sullen as to be somewhat self-destructive, she turned things around so that it was all on her mother for not telling her something she could have found out if she'd asked.
We can apply this logic to the Housening to see why it is that John feared April's grudging compliance almost as much he did her screaming refusal to turn her life around so he could play with TRAAAAAIIINNNSSSS!!! FOR; the douche's refusal to admit that he was being unfair, unfeeling and unkind would have went "CHEE!!!" and defamed her for making him worry over nothing.