Why do you need to gather contacts?
Far better to get warm leads after they have viewed the service on offer. Which I have now looked at and can't see a demo. All you want me to do is sign up.
There are no contact details on the site. That would be enough to make me wary.
The calendar UI is very dated (and doesn't work very well) and the copy is badly written. I'm assuming English isn't your first language.
And it's not responsive. So that's going to put a lot of people off.
I think you will find there are indeed contact details on the site, there is a contact page in the footer on every page, as well as a Hotjar contact form and a companies house contact.
The calendar UI is a plug-in and achieves the job for an MVP in our opinion, and without having made an account (which I can see you have not) there is no way you would be able to tell if it works well or not as it is disabled until an account has been made.
I assure you the copy and language is all correct and English is all of our first language, and with respect I do not feel we need to take grammatical advice from yourself considering your posts.
I’m not sure how responsive you expect an MVP to be, and I am not sure if you are viewing on mobile or desktop, but again we feel the desktop version is responsive enough, and is not a vital aspect in an MVP.
To be completely honest we are feeling as though this isn’t constructive criticism coming from yourself. Due to the fact there are a few points you have raised which we strongly feel are unfair and others that we know there is no way of you fairly judging, I don’t think it would be a good decision on our behalf to take your opinions on board and will wait for other responses that may appear less hostile.
Apologies.