Wait I'm confused..what's IP? XD (I'm sorry, I've been playing League for only 5 months now)
I don't really understand your point but even if its slower now to gain BE than it was before its still more BE income in the long term if you spam than if you play a couple games a day. If you play casually the only real income you're getting is for first win of the day and then occasionally from levelling up. If you spam, you get First Win, faster levelling up rewards, honor rewards faster as well because if you're playing lots, you conplete honor stages faster which unlocks keys for chests (which may contain a champ u want or BE). In addition playing a few games a day gives a small window to hpw many games you can win for that day. For example, if you play casually and you played like 3 games in a day compared to someone who spams and plays 20, the spammer is more likely to have won more games. Winning more games gives more xp which helps level up faster and get BE.
I'm sorry I didn't really understand your point and sorry if I just sound like a broken record but I really do feel you're gonna generate a lot more BE income in a year if you're a spammer than if you're only playing a few.