As a partner 95% of our installations are performed by our engineers, including a workshop with on-site training. But sometimes customers do not want to pay for this added value / cost and perhaps competitors charge only one day for an installation
Last week I had a client who was dissatisfied with Veeam: he'd done the install himself and the write speed was 'bad'! Turns out he routed his backup traffic on a 1GbE connection (although he has a 10GbE backup network), plus he had very good dedup & compression ratios, therefore big reads in (on-host Hyper-V), small writes out (if you share 100MiB/s with 4 jobs you get 25MiB/s each). Just a small re-configuration and teaching him how to interpret the results was enough.
This week's client actually said the following after the workshop: "Wow, I thought you guys screwed us and planned way too many days for the configuration, but now that I see what Veeam can do, I totally get it".
You can break anything with a bad design!