@fkakar - Sorry to hear about your WP rejection. For any of us to comment on the merits and possible next steps, we would need more information like:
1) Current citizenship
2) Country of application
3) Any past visa applications to Canada and their status
4) Any past visa rejections or overstays in an country
5) Incubator/VC/Angel track record
6) Your personal profile in startups
7) Current startup innovation level and revenue metrics
8) Country you appled from
These are just some of the factors that could be impacting your WP rejection.
Having a SUV LOS does not gurantee WP, you are still assessed on your individual risk factors, like are you likely to overstay if for some reason your SUV PR is rejected. Based on my limited knowledge, for some reason IRCC thinks you are at a high risk of overstaying if your PR is rejected. And secondly, they seem to doubt the genuineness of your startup.