Freelance bidding websites flawed?

This week I signed up to a popular freelance site. A website where clients and agencies post projects for freelancers to bid on and win work. On the outset I thought that this seemed like quite a good way to win work.
After filling in all of the relevant data and creating a freelance profile, I started looking through some live projects. Everyone which I came across gave little information on the scope of the project. Here's a few anonymous examples.

We need business cards for 22 persons, from 3 different websites and with a range of different logos. We provide details and business card template, we need someone to do the job on Photoshop for us. The job should take around 2 days, please send me a quote if you are interested. Regards.

The problem with the above is that the client is dictating what software the designer needs to use. No professional designer will use Adobe Photoshop to layout business cards. Doing so will create problems with pre-press and cause the client extra cost when the project goes to print. The client is also supplying the template which is to be used, this will need to be checked, and possibly re-created, to ensure it's press-ready. They then dictate how long it will take whilst supplying no guide to budget allocation.

I need a designer to create various info-graphics from supplied data. They will be working on a number of different client projects. The designer must take the data, and the brief for the graphic and come up with a design in keeping with the clients' bands. The first project will involve taking data collected about Facebook and representing it for non-technical, non-it literate business professionals.

This one is a little better and the client provides a little more information. However, there is still plenty of relevant data missing; Where will the info-graphic be used – print or digital, or both? How much data is to be supplied to the designer and how will that be supplied? No examples of the client's brands are given. Will logos etc., be supplied?

Now on the outset my above comments may seem a little nit-picky. However, to do either of the above jobs professionally and profitably (for both parties) all, plus more, of that information is required. A discussion needs to take place and the above concerns need to be raised. Advice about using the correct software along with some guidance will save the client time, money and a lot of hair-pulling. It will also make the designer's job a lot easier. The main problem is that when you try to bid on those projects, with the aim of giving a rough ball-park figure at the outset along with some advice, the website forces you to give a specific cost for the job along with a detailed proposal. Which is totally impossible to do.

Consider the following scenario. You send an estate agent an electronic form for them to fill in. Your brief at the top of that form is ‘I would like to buy a house. I want that house in 1 week and it needs to perfectly accommodate my lifestyle and my family's requirements’. No other information is given. The fields which the estate agent can fill in to win your project are as follows:

  1. Proposal
  2. Price of house
  3. Expected deposit

I can't imagine that either party would get very far.

So are these types of websites fundamentally flawed?