I agree but I don't see any personal attacks in this thread. I do however think a healthy debate is good as long as the subject is relevant to the topic of the thread.
I too have no issue with some debate and don't feel as though this was a personal attack
I think there may be some confusion as the OP was discussing and questioning the use of liquid yeast and the other poster is discussing the use of dry yeast-at least that is what I am interpreting.
So............ as I previously stated and stick by: it is highly recommended that when using a liquid yeast, a starter should be made to achieve the proper pitch rate. The reason for this is that by the time the end user is ready to pitch the yeast the initial cell count/viability of the pack is generally less than what was originally packaged. While the package states they are adequate for beer up to 1.060, this is usually not the case based upon the viability.
In the book "Yeast" Chris White and Jamil both discuss this and the proper way to make a starter to achieve the desired pitch rate for the batch of beer and while the pack states one thing, they somewhat contradict this by discussing the need for a starter. A starter does two things- verify the viability of the existing cells and growing the yeast to the proper pitch rate. BTW, I highly recommend this book!
The yeast calculators that are out there do not only address the use of the slurry but also using both new dry yeast and liquid strains. IMO, Mr. Malty does a better job when using slurry and Yeastcalc does a better job when using new packages of yeast or if stepped starters are required.
When using dry yeast it is normal to just pitch the yeast. It is recommended to rehydrate but appears to be less of a factor. There are also two different size packages available and if using an 11gram pack, they are usually more than adequate to ferment any gravity size of beer. The production of dry yeast prevents degradation of cells and contains a lot of nutrient that allows for direct pitch with little consequence. When using the smaller packs there is possibility that 2 packs may be required for bigger beers and both calculators can help determine this.
The bottom line is this: Whatever you choose to do, the yeast will ferment the beer with or without a starter or with or without rehydrating. The potential for stress, off flavors or stalled/incomplete fermentation increases with the use of liquid yeast used without a starter.
In my own personal experience I have seen improvement in the attenuation of my beer, decrease in lag time(Growth phase) and improved quality of my final product. I can site actual side by side tastings of some of my earlier beer compared to those that have been made with improved process. In addition, I find that I can now consistently reproduce each beer I make time and again.
Obviously, there are many more factors involved in the production of quality beer but it is the yeast that makes the beer first and foremost. If you take care of the yeast and handle it properly each and every time you brew beer, the final product will be improved. Pitch rate, aeration, temperature control, nutrients are all important factors to consider when handling each strain of yeast for each batch of beer.
If you want to make things simple, use dry yeast and use the 11 gram packs. If you want to be able to brew certain styles of beer then the only choice you may have is to use liquid strains available and making a starter should be part of that process.