TRV rejections are higher than normal for spouses compared to regular visitors, yes, but a large part of whether your application is successful or not depends on how well put together it is.
My wife applied for a TRV, she was married to me at the time, from Vietnam (a country requiring biometrics to enter, also Vietnamese in general have a hard time getting TRVs), is not rich, a lot of people on these forums told me it was a 99% chance of refusal, and then she got a multiple entry for life of passport TRV. We spent 3 days creating the TRV application, extremely detailed in everything we submit.
A lot of common mistakes I see people make are:
1) Purpose of visit: Saying something generic like "wanting to spend time with my husband" instead of "Spending time with my husband, will also go tour Alberta, will visit this landmark, will stay at this hotel, will take tour bus to get there, I will stay in his house while he's at work", etc.
2) Length of stay: Asking for several months of stay rather than a few weeks.
3) Finances: Having the sponsor deposit large amounts of money into bank account.
4) Previous TRV refusals: Applying for a TRV despite lots of refusals before
5) Buying plane tickets before approval rather than sending an itinerary.