I don't know what the general "mood" is regarding sports betting in North America, but in the UK the arguments you see generally fall into three "streams".
"Too much betting advertising/sponsorship on TV"
Admittedly, I see the point here, but the revenue/sponsorship argument is the flipside. In addition, given the sheer number of people with TiVo-style recorders, you could argue ads are becoming an irrelevance anyway as people just pause for a break then fast forward until the game restarts.
"Betting shops are a blight on our streets/society/civilisation as we know it".
Here you get the argument that betting shops are sort of low-class or seedy and they shouldn't be such a visible sign of gambling. I personally don't subscribe to this, but then again, maybe I'm so seedy and low-class myself I just don't notice. Again, the flipside is that any adult can walk into any store and play the National Lottery, which is surely a far more pervasive form of visible gambling, along with being a game of random chance.
Which leads on to...
"Gambling targets the vulnerable"
There's a huge range of ways you could spend your gambling money, be that lottery tickets, scratchcards, casino games, virtual sports and so on. The argument is this temptation shouldn't be in such plain view, or that some people basically need saving from themselves.
The flipside is that, in many forms "gambling targets the idiots". It amazes me how many people play casino games, slots, lottery etc. armed with their "superstition" or "secret tactics". I know coarse language is a no-no on the forum, but in this case I can only say "WTF are you thinking??". You'd think somebody playing a game of random chance might click that the words "random" and "chance" give a heavy hint, but seemingly not.
Same with sports betting, the times I see people putting on accumulators (soccer the overwhelming favourite) which consist of combos of short odds or pure home picks with NO CLUE who some of the teams are or the standard of league they play in. Pick 1 might be the English Primer League, pick 20 might be the Sudan Third Division. If your "strategy" is the betting equivalent of wearing a blindfold and sticking pins in a map, why are you so shocked when you lose?
The "vulnerable" argument only goes so far. Should we ban beer because some people are alcoholics? Ban fatty food because some people seem intent on making themselves a human version of the Stay=Puft Marshmallow Man?
I have may own "secret tactic" with slots and casino games - I DON'T PLAY THEM. I stick to sports betting because at least you have a real-life event with real-life form you can actually research.
Again, apologies for length, I assure you I'm not trying to earn the "highest Average Words to Posts ratio" forum badge.